1. Field of the Invention
The present general inventive concept is related to image forming apparatuses that include a transfer unit to form images on a recording medium by way of a developing agent and whose operation depends on installation of a predetermined component. More particularly, the present general inventive concept is directed to an image forming apparatus in which a driving force is selectively transferred to the transfer unit.
2. Description of the Related Art
An electrophotographic image forming apparatus transforms image data provided from an external host device into a visible image on a recording medium by applying a developing agent to the recording medium to correspond to the image data. The image forming apparatus typically includes a transfer unit to transfer the developing agent to the recording medium that ultimately forms the visible image. The transfer unit is detachably mounted in the image forming apparatus and is driven by a driving force provided by a driving unit when mounted in the image forming apparatus.
A typical transfer unit of an image forming apparatus is that of an intermediate type, in which an intermediate transfer belt is interposed between a latent image holding member and an intermediate transfer roller. Typically, a driving roller engages the intermediate transfer belt through friction and rotates the intermediate transfer belt thereby in an endless track mode. When the transfer unit is properly mounted in the image forming apparatus, the driving roller engages with a driving unit through which the driving force rotates the intermediate transfer belt.
In apparatuses where the transfer unit is detached in a direction perpendicular to the direction in which the driving roller engages with the driving unit, the driving roller is first disengaged from the driving unit prior to the transfer unit being removed. However, the subsequent mounting of the transfer unit must include re-engaging the driving unit so that a printing process may be carried out successfully.
If the printing process is attempted when the driving roller is disengaged from the driving unit, the intermediate transfer belt of the transfer unit fails to rotate, resulting in excessive friction between the surface of an image holding member and the intermediate transfer belt. Thus, the image holding member and the intermediate transfer belt are excessively worn and image quality on the printing medium is greatly diminished.